Greenhouse Heating Sources

The right heating source will make your greenhouse bloom.

Plants survive and thrive in greenhouses despite harsh outdoor temperatures. It is vital to keep the temperature at a steady, consistent and warm level throughout the greenhouse. The sun can provide up to a quarter of the heat, but other sources must be found, especially during the nighttime and winter hours. Various heating methods can provide this function, and they differ greatly in cost, space, efficacy and material requirements. Evaluate your greenhouse needs and the different options when choosing the right methods for your structure.

Space Heater

An electric, 220-volt space heater is an effective albeit relatively expensive method of heating a greenhouse. Set it to a timer to avoid excess heating and unnecessarily raising your electric bill. Space heaters are clean, safe and efficient. Another option is to use a heater that is fueled by oil or gas. Purchase one that can be installed in a masonry wall. It is very important to ensure proper ventilation when using gas, oil or wood.

Water Barrels

Solar heating saves money and provides an effective way to heat a greenhouse. Large barrels of water provide an easy and inexpensive way to accomplish this. Paint large containers black to help retain heat. Fill them with water. If you are concerned about freezing, add antifreeze to the solution. During the day, the water will be heated by the sun, and the heat will flow out during the night.

Compost

Passively heat the greenhouse with compost and save money. Place the compost in a barrel or crate to heat up as it decomposes. The carbon dioxide may also rise in the greenhouse, which has its own benefits in production. Consider using black plastic or landscaping fabric around the composting barrels. Aerate the pile by using pallets, PVC pipes with holes or other methods that allow for air flow. Odor can be an issue with this tactic.

Various Methods

Gardeners use a variety of other methods to heat greenhouses. Christmas tree lights emit some warmth, do not use up a great deal of electricity and provide an aesthetically pleasing element, especially during the holiday months. A floor woodstove will also heat the greenhouse effectively. Make certain that you have a chimney or other safe method for the smoke to escape.

Considerations

The more insulation you have in your greenhouse, the less money, time and space you will spend on heating. Gardeners use insulating blankets and plastic to aid in this process. Circulating the air will also keep the plants warmer because cold air tends to sink. Make sure to adhere to all safety standards of the heating method you choose, especially if using fire. Automatic shutoff switches and other precautions can prevent a problem.

About the Author

Suzanne Rose has worked as a copywriter for more than 10 years. She has served in various positions for advertising agencies and marketing departments, with work appearing in print and online publications. Rose specializes in topics related to parenting, crafts, health and business. She holds an M.B.A.